An Etymological Dictionary of Astronomy and Astrophysics

1. Statistics: A number assigned to each value or range of values of a given quantity, giving the number of times this value or range of values is found to be observed.
   

2. Statistical mechanics: A multiplicative factor in the expression for the probability of finding a system in a given
   quantum state. Usually the number of degenerate substates
   contained in the state.

See also: → statistical; → weight.